In order to improve the results of allografts about the knee in humans and animals, isolated parameters will be studied in a sequential fashion. In particular, the immune response and storage techniques will be studied with respect to their harmful effects on the graft, and attention will be paid to prevention of these harmful effects. Four models will be developed. The first is the rat distal femur allograft model which will be used primarily for the study of the immune response and its prevention. It will also be used to determine optimal techniques for storage. The dog shell allograft model will be used to determine whether or not improvement occurs with inhibition of the immune response. The dog total knee joint composite graft will be used to determine whether or not improvement occurs with inhibition, and it will be compared to a prosthetic total joint replacement in the dog. A vascularized total knee joint model in the cat will be studied to determine whether immune inhibition can maintain vascular patency.